SimonNOS
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| posted on 12/11/02 at 07:30 PM |
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Seamed vs Seamless
Does it make much difference weather you use seamed or seamless tubing for the wishbones?
Seamless is stronger right? But can you get away with seamed?
Cheers, Si
Renault Clio 16v with NOS
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ProjectSRP
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| posted on 12/11/02 at 08:11 PM |
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If I were you I would try and get some DOM tubing. Not only is seamless DOM stronger because of the cold working but also a higher grade of steel is
usually used. Can't be too safe when it comes to suspension.
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Lars
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| posted on 18/12/02 at 12:40 AM |
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Lars
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| posted on 18/12/02 at 12:43 AM |
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it seems quite hard finding seamless tube, does anyone know if seamed will be strong enough.
I've seen a pic in the book where the trailing arms are made using seamed tubing, and also some people on this site use seamed oval tubing???????
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chrisg
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| posted on 18/12/02 at 06:34 PM |
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Hydraulic supply places usually have seamless.
Cheers
Chris
Note to all: I really don't know when to leave well alone. I tried to get clever with the mods, then when they gave me a lifeline to see the
error of my ways, I tried to incite more trouble via u2u. So now I'm banned, never to return again. They should have done it years ago!
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Viper
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| posted on 18/12/02 at 06:45 PM |
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any decent steel stockholder should have CDS (cold drawn seamless) that's what i have used for mine, 25mm O/D 18swg but the wishbones tiger supplied
me (not using them) are a lot heavier i am guessing they are 10swg and i believe they are seemed...
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Viper
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| posted on 18/12/02 at 06:46 PM |
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oh and i paid £12.00+vat for 6 mtrs
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Liam
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| posted on 19/12/02 at 01:38 AM |
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I'm using the same seamed oval that MK uses on his wishbones. I rather doubt it's gonna just fall apart, probably not even in an accident that rips
a wishbone off - then it's academic anyway. I'm not worrying about using seamed.
I will, however, be getting my wishbones professionally [TIG] welded. That's something really worth thinking about. The quality of
welding is far, far more critical than the seamed-vs-cds issue when it comes to the wishbones.
IMO of course.
Liam
[Edited on 19/12/02 by Liam]
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Rorty
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| posted on 19/12/02 at 05:10 AM |
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Of the seamless "mild" steel tubing, CDS is the strongest, followed by CDW/DOM.
Then there is welded mild steel tube (ERW), which shouldn't be confused with black/galvanised pipe, which is also welded. You should only be using
tube.
You could use ERW, but it would be worth doing a few sums first to check suitability. I would have thought 25.4mm x 2.6mm ERW would do the job.
I would only use CDW/DOM and CDS. It's dimensionally more acurate, and inherently stronger. OMO.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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Dick Axtell
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| posted on 19/12/02 at 02:32 PM |
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quote:
Originally posted by chrisg
Hydraulic supply places usually have seamless.)
MK told me never to use the seamless hydraulic tubing, because it's been heavily annealed. This means that it bends easily, (for hydraulic circuits -
used it myself in rig-building), and will therefore do so under "bump" loading.
Be warned - others have discovered this to their cost!!
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philgregson
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| posted on 20/12/02 at 04:06 PM |
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I must admit that I was just going to use ERW like the rest of the chassis (but round obviously). If you stick a bit in the vice and bash F*** out of
it (Highly technical I know and perhaps taking the technological approach too far. ) you can cause more damage than I would want to see on my car and
it's primary failure mode doesn't seem to be one of falling apart at the seams.
Now I know that this probably is only an approximation of the wishbone loadings on a locost but it indicates to me that the welded seam is probably
not too much of a problem. If we were applying pressure from the inside it might be a diferent thing - but we are not.
Once again I might be talking rubbish but your views would be appreciated.
Phil.
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interestedparty
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| posted on 20/12/02 at 05:26 PM |
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quote:
Originally posted by philgregson
Now I know that this probably is only an approximation of the wishbone loadings on a locost but it indicates to me that the welded seam is probably
not too much of a problem.
Seems reasonable to me. After all, we are all relying on the strength of welded joints, why should the wishbone tubes be any different? Might be
important if weight was a critical issue, and the thinnest possible tube was needed
John
As some day it may happen that a victim must be found,
I've got a little list-- I've got a little list
Of society offenders who might well be underground,
And who never would be missed-- who never would be missed!
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Alan B
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| posted on 20/12/02 at 11:02 PM |
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Guys consider a seamed tube that has come "unseamed" unlikely, but bear with me.
I t will stiil have the same tensile strength as full tube and the full compressive strength. The three things that are afected adversly are a)
torsional stiffness, b)beam stiffness, and c) buckling strength.
Consider a), this should not be an issues, as there should be no torsional loads on any wishbone tube.
b) again should not be an issue, there are no bending loads (except for the lower wishbone I guess)
c) depends a lot on the tube length. a relatively short tube with a thick wall should not be affected too much.
So I would say with a good choice of material, seamed tube should be OK IMO. Although DOM/seamlees is better.
I'd also agree with Liam that quality of welding is a bigger concern than tube selection.
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